Gas-fired heating appliances



Feb. 21, 1967 R. K. LYNES 3,304,985

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United States Patent Ofiice 3,304,985 GAS-FIRED HEATING APPLIANCES Roberts Kitchener Lynes, Birmingham, England, assignor of one-half to Bullfinch (Gas Equipment) Limited, Birmingham, England, a British company Filed Mar. 25, 1965, Ser. No. 442,614 Claims priority, application Great Britain, Apr. 21, 1964,

16,431/ 64 Claims. (Cl. 158-99) This invention relates to gas-fired heating appliances and more especially to appliances for heating railway lines in the vicinity of railway points to preserve operation of the points in freezing conditions.

In accordance with the invention a gas burner comprises a burner tip and a gas-permeable collection of discrete ceramic particles located in the path of flow of gas from the combustion chamber defined between the burner tip and said particle collection. Preferably the discrete ceramic particles are constituted by ceramic balls.

A typical example of the practical realisation of the invention is described with'reference to the accompanying drawings, wherein:

FIGURE 1 is a part-sectional plan view showing a heating appliance according to the invention as applied to a railway line;

FIGURE 2 is a sectional side view of a part of the appliance shown in FIGURE 1 but on an enlarged scale;

and

FIGURE 3 shows schematically the application of a bank of heating appliances to a railway line.

In the illustrated embodiment of the invention a gas fired heating appliance for heating railway lines comprises a dish shape housing such that the open side 11 of the housing can be disposed in close proximity to the web 12 of a railway line 13. The housing 10 is formed with a central aperture 14 in register with the tapped bore of a sleeve 16 welded to the exterior of the housing. The sleeve 16 receives one screwed end of a connecting tube 18, and the other end of the latter is threaded for adjustable length connection into an internally threaded mounting tube 19 fixed to one side of a manifold 20. The manifold 20 extends parallel to the rail 13 and is common to a group of say five heating appliances, as illustrated in FIGURE 3.

The screw tapped bore of the sleeve 16 receives from the interior of the housing the externally screw-threaded hollow spigot end of a burner 16. A shoulder between the spigot end 15 and the remainder of the body 17 of the burner seats on the interior surface of the housing, and a filter gauze 30 is interposed between the adjacent ends of the spigot 15 and connecting tube 18. The spigot 15 is screw tapped to receive a perforate burner tip 21 of refractory material through which gas can fiow from the connecting tube 18 into the combustion chamber 22 defined within the burner body. The opposite side of the combustion chamber 22 to the tip 21 is bounded by a perforated platform 23 of refractory material spanning the chamber and resting upon an internal shoulder in the burner body. A number, fifty for example, of balls 24 of ceramic material, for example that known as Steatite," are accommodated in a metal cup 25 welded at its base to the end of the burner body 17. The balls 24 rest in say two layers on the platform 23 and are retained by a disc 26 of expanded metal mesh. The disc 26 is held in position by inturned tongues 27 which also define castellations 28 in the rim of the cup 25 which can be used to receive the complementary end of a key for screwing the burner 16 into and out of the sleeve 16 for servicing purposes.

In use, combustible gas is supplied through the gas/air Patented Feb. 21, 1967 mixer 29 so that a gas and air mixture passes through the manifold 20 and each connecting tube 18 to the burners 16. In each burner the gas/air mixture passes in turn through the filter 30, the burner tip 21, the combustion chamber 22, the platform 23, the collection of ceramic balls 27, and through the mesh 26 into the housing 10 against the rail 12. The gas/ air mixture is ignited, for example through a hole in the housing or electrically by a spark and the gases burning within the housing bring about incandescence of the burner 16. Initially the gas/ air mixture burns externally of the mesh 26 but as the burner is raised to incandescence so the zone of ignition of the mixture gradually retreats through the mesh, ceramic balls and platform to lie principally within the combustion chamber 22.

In an alternative construction the housing 10 and burner body 17 have registering holes which permit direct ignition of gas in the combustion chamber 22 from the exterior of the housing, with subsequent heating of the burner body and the collection of balls 27. These holes also permit a visual check as to whether the burner is alight. It is also envisaged that the conventional ceramic burner tip 21 can be replaced by a perforate metal disc with the advantage that the latter type of tip provides quieter operation.

In addition to constituting an efiicient heat radiator, the presence of the collection of balls 27 has the following important advantages. The ceramic balls have a relatively large heat capacity and therefore retain a high temperature for a substantial time so that should the burning of the gas mixture be extinguished, for example by the great air turbulence occasioned by a passing high speed train, the balls serve to reignite the gas after subsidence of the turbulence. Further the presence of the balls before the combustion chamber assists in isolating the combustion chamber from the air turbulence and materially reduces the frequency of the burning gases being extinguished by the turbulence. Furthermore, since the ceramic balls are not fixed to one another they are not susceptible to fracture as a result of vibrations set up by the passing of trains over the line.

I claim:

1. A railway line heater assembly comprising a housing having an open side adapted to be applied to a rail and containing an internal combustionchamber, means providing a gaseous fuel inlet through said housing to the combustion chamber, a perforated burner tip disposed in the path of said fuel flowing into said combustion chamber, and means at said open side of the housing mounting a heat radiator in the form of a gas permeable collection of discrete ceramic particles disposed in the path of the products of combustion leaving said combustion chamber, said particles serving as a barrier to shield the combustion chamber from external air turbulence at said open side of the housing and said particles having a relatively high heat capacity so as to retain high temperature for a long time whereby they may automatically reignite the fuel after such relatively short periods that burning may be unintentionally extinguished in the combustion chamber as by excessive air turbulence entering said open side of the housing.

2. In the heater assembly defined in claim 1, said particles comprising a group of loosely related ceramic balls mounted in a perforated retainer.

3. In the heater assembly defined in claim 1, said combustion chamber being confined within a tubular member that has the burner tip mounted on one end at said inlet and said collection of ceramic particles supported on the other end adjacent said open side of the housing, and means fixedly mounting said tubular member in the housing.

3,304,985 3 4 4. In the heater assembly defined in claim 3, the mount- References Cited by the Examiner ing of said ceramic particles comprising a perforated platform bridging said combustion chamber, a cup-shaped UNITED STATES PATENTS member fixed to said platform to laterally confine said 1,259,029 3/1918 Lucke 15899 particles, and a perforated retainer extending across the 5 1,330,048 2/1920 Baker. cup-shaped member above the platform. 2,227,899 1/ 1941 Grubb.

5. In the heater assembly defined in claim 3, said tubu- 3 204 094 8 1965 Huisinga 126-2712 X lar member being threadedly attached to said housing at said inlet, and said particles being mounted in a perforated FOREIGN PATENTS retainer fixed to said tubular member and formed to re- 10 538,298 3/1922 France. ceive a tool for turning the tubular member in its threaded attachment connection to the housing. CHARLES J. MYHRE, Primary Examiner. 

1. A RAILWAY LINE HEATER ASSEMBLY COMPRISING A HOUSING HAVING AN OPEN SIDE ADAPTED TO BE APPLIED TO A RAIL AND CONTAINING AN INTERNAL COMBUSTION CHAMBER, MEANS PROVIDING A GASEOUS FUEL INLET THROUGH SAID HOUSING TO THE COMBUSTION CHAMBER, A PERFORATED BURNER TIP DISPOSED IN THE PATH OF SAID FUEL FLOWING INTO SAID COMBUSTION CHAMBER, AND MEANS AT SAID OPEN SIDE OF THE HOUSING MOUNTING A HEAT RADIATOR IN THE FORM OF A GAS PERMEABLE COLLECTION OF DISCRETE CERAMIC PARTICLES DISPOSED IN THE PATH OF THE PRODUCTS OF COMBUSTION LEAVING SAID COMBUSTION CHAMBER, SAID PARTICLES SERVING AS A BARRIER TO SHIELD THE COMBUSTION CHAMBER FROM EXTERNAL AIR TUBULENCE AT SAID OPEN SIDE OF THE HOUSING AND SAID PARTICLES HAVING A RELATIVELY HIGH HEAT CAPACITY SO AS TO RETAIN HIGH TEMPERATURE FOR A LONG TIME WHEREBY THEY MAY AUTOMATICALLY REIGNITE THE FUEL AFTER SUCH RELATIVELY SHORT PERIODS THAT BURNING MAY BE UNINTENTIONALLY EXTINGUISHED IN THE COMBUSTION CHAMBER AS BY EXCESSIVE AIR TURBULENCE ENTERING SAID OPEN SIDE OF THE HOUSING. 